The term “streaming video” generally refers to the reception of multimedia content, such as television programming and other audiovisual content, through a communications network at a bitrate enabling presentation of the content in real time as it is received. Streaming video may be viewed live or on-demand and transmitted by, for example, a VOD provider, a remotely-controlled placeshifting device, or a pay television provider delivering television programming via cable, satellite, or Internet (OTT) distribution channels. In the case of VOD or OTT television services, the media content may be stored in a pre-encoded format and distributed to a client media receiver, such as a mobile phone or STB, over a CDN. In the case of placeshifted media, a DVR, STB, or a similar device having placeshifting capabilities and located within a user's residence may encode and transmit selected streaming video to a client media receiver, such as a mobile phone or tablet, operated by the end user.
Media streaming services enhance the ease and convenience with which end users view streaming video content, such as VOD, OTT television, and placeshifted media content. Media streaming services are, however, inherently limited by resource constraints affecting network reliability and bandwidth availability. When network bandwidth becomes overly constrained during a streaming video session, latencies may occur resulting in prolonged buffering and other delays in the presentation of streaming video content. Network latencies can also result in sluggish response times in implementing user-issued commands during a streaming video session, such as channel change commands issued by a user when streaming OTT television content. Various ABR streaming techniques are now widely employed to enhance streaming video performance despite such variances in network bandwidth and other constraining factors. In general, ABR techniques actively adjust encoding parameters (e.g., image resolution and video framerate) in response to variations in network bandwidth, playback device resources, and the like.
Bandwidth constraints are more likely to arise when a streaming media server concurrently or simultaneously delivers separate media streams to multiple playback devices (herein, “client media receivers”). This may occur when, for example, the streaming media server assumes the form of a consumer placeshifting device located in a user's residence or household. In this case, the streaming media server may concurrently provide video-containing media streams to multiple different client media receivers to, for example, allow a first person in the household to view chosen content on a display integrated into or coupled to a first receiver (e.g., a mobile phone or tablet), while a second person in the household views media content on display integrated into or coupled to a second receiver (e.g., television). Should bandwidth constraints arise, both client media receivers may experience a degradation in playback quality. While ABR techniques can be applied to improve playback performance in such instances, the provision of lower bitrate streams, such as streams having decreased resolutions, may be noticeable to end users viewing streaming video content on certain display devices, such as devices having larger display areas and higher resolution capabilities. A similar issue may likewise arise when a streaming media server lacks sufficient capabilities (e.g., due to hardware limitations) to simultaneously encode two or more separate video streams at maximum quality levels and streaming bitrates.
There thus exists an ongoing demand for systems, methods, and devices capable of optimizing streaming bitrate during a multiclient streaming session when bandwidth constraints, server limitations, or other such limiting factors prevent a streaming media server from concurrently encoding segments of all outgoing video streams at the highest possible bitrate. Other desirable features and characteristics of embodiments of the present disclosure will become apparent from the subsequent Detailed Description and the appended Claims, taken in conjunction with the accompanying drawings and the foregoing Background.